osize too small

osize too small

[Guy Rouillier]

I'm using ppp with pptp to connect to a MS server at work.  Kernel is
2.6.3 AMD64 on Mandrake 10.0, ppp 2.4.2.  I built this kernel myself to
fix the 64-bit issues with ppp (fix previously reported.)   When I have
VPN up and run a browser, it will retrieve a particular page fine the
first time.  However, if I click the submit button on that page again
(which transmits a bunch of data - I authored this page so know all
about it) the browser just goes into continuous wait and never actually
transmits anything.  I see the following in dmesg:

PPP generic driver version 2.4.2
ppp_mppe: module license 'BSD without advertisement clause' taints
kernel.
PPP MPPE Compression module registered
Module ppp_mppe cannot be unloaded due to unsafe usage in
include/linux/module.h:503
mppe_compress[0]: osize too small! (have: 1400 need: 1404)
ppp: compressor dropped pkt
mppe_compress[0]: osize too small! (have: 1400 need: 1404)
ppp: compressor dropped pkt

What is the appropriate fix for this? ifconfig shows an MTU of 1396 for
ppp0.  I tried specifying mtu 1500 when starting pppd, but it still ends
up 1396.  I suppose the server end is constraining it.  Appreciate all
suggestions - I can rebuild the kernel if necessary.

-- 
Guy Rouillier